Coupling nut and hold-down construction method
A coupling nut includes: a simple fastening nut housing case having bolt insertion holes for insertion, from end portions of the simple nut housing case, of bolts to be coupled, and, in sections of the housing case toward end portions thereof, simple fastening nut housing portions configured to non-rotatably house simple fastening nuts that screw together with the bolts inserted into the bolt insertion holes; and a simple fastening nut that is housed in each simple fastening nut housing portion of the housing case, provided with at least two or more nut segments that are biased by biasing springs, and configured to screw together with a screw portion of the inserted bolt when the housing case is rotated in a screwing direction after insertion of the bolts. One simple fastening nut has a left-hand thread and the other has a right-hand thread.
1. A coupling nut comprising:
a polygonal cylindrical member having neither internal nor external threads and having a polygonal internal and external shape in radial planes of the polygonal cylindrical member, the polygonal cylindrical member having two mutually opposite end portions, an end of each of the end portions constituting a respective end of the polygonal cylindrical member and through each of the ends of the polygonal cylindrical member is formed a respective bolt insertion hole configured for insertion therethrough of a respective bolt, each respective bolt insertion hole being formed by a respective annular end wall of the polygonal cylindrical member, the polygonal cylindrical member being of greater internal diameter at the end portions than a smaller internal diameter portion contiguous with the end portions, a respective radially inwardly extending annular surface being formed by annular walls of the polygonal cylindrical member at each respective transition from the greater internal diameter at a respective one of the end portions of the polygonal cylindrical member to the smaller internal diameter portion of the polygonal cylindrical member,
the coupling nut further comprising two simple fastening nuts, each respective one of the simple fastening nuts being of larger diameter than the smaller internal diameter portion of the polygonal cylindrical member, each respective one of the simple fastening nuts being non-rotatably received in a respective one of the end portions of the polygonal cylindrical member and configured to have a respective one of said bolts screwed therethrough, each of the simple fastening nuts having a same polygonal shape in axial planes of the simple fastening nut as the polygonal internal shape of the polygonal cylindrical member and being sized so as to fit into the respective end portion non-rotatably relative to the polygonal cylindrical member, the simple fastening nuts together with the polygonal cylindrical member forming a continuous passage from one of the ends of the polygonal cylindrical member to the other of the ends of the polygonal cylindrical member, and one of the simple fastening nuts having a left-hand internal thread and no external thread and the other of the simple fastening nuts having a right-hand internal thread and no external thread, each of the internal threads being configured to engage threads of a respective one of said bolts; and
wherein each respective one of the simple fastening nuts comprises respective nut segments in which the internal thread of the respective simple fastening nut is formed and a respective simple fastening nut housing case in which the respective nut segments are non-rotatably received, the respective simple fastening nut housing case forming a radially inwardly extending annular surface on which a washer comprising a flat spring is supported, the flat spring being configured to bias the nut segments toward the end of the end portion of the polygonal cylindrical member in which the respective simple fastening nut is received and wherein each of the simple fastening nuts abuts against a respective one of the annular end walls of the polygonal cylindrical member and also abuts against a respective one of the radially inwardly extending surfaces whereby each of the simple fastening nuts is fixed against axial movement in the polygonal cylindrical member.
2. The coupling nut according to claim 1 , wherein:
the simple fastening nuts housed inside the housing portion in both end portions have differing inner diameters.
3. A construction method comprising:
fixing an anchor bolt to a foundation of a building;
coupling a first through bolt to the anchor bolt by means of a first coupling nut therebetween; and
attaching the first through bolt to a first beam of the building above the foundation by passing the first through bolt through a through hole in the first beam and screwing a first washer-fitted simple fastening nut onto a portion of the first through bolt projecting above the through hole, wherein
the coupling nut is the coupling nut of claim 1 .
4. The construction method according to claim 3 , further comprising:
coupling a second bolt to the first bolt by means of a second coupling nut therebetween; and
attaching the second through bolt to a second beam of the building above the first beam by passing the second through bolt through a through hole in the second beam and screwing a second washer-fitted simple fastening nut onto an end portion of the second through bolt projecting above the through hole in the second beam; and, optionally,
attaching at least one respective additional through bolt to at least one successively higher respective additional beam by screwing a respective additional washer-fitted simple fastening nut onto a portion of the respective additional through bolt projecting above a through hole in the respective higher beam through which the respective additional through bolt is passed, and coupling, by means of a respective additional coupling nut therebetween, the respective additional through bolt to the through bolt connected to the next lower beam, wherein
each of the coupling nuts is the coupling nut of claim 1 .